During military operations or mass casualty situations, trauma surgeons are called on to place external fixation without the use of fluoroscopy. However, the safety and efficacy of this procedure has not been investigated.
Orthopedic surgeons, with varying experience, externally stabilized 20 fractured cadaver femora and tibiae. Using Behrens’ safe zones, 194 half-pins were placed without radiographic assistance
. Subsequently, fluoroscopy and dissections documented pin positions.
Of the 194 pins, there were three (1.5%) neurovascular injuries (popliteal artery trifurcation). Forty-nine percent (95 of 194) of pins were overpenetrated (greater than two threads out the second cortex), with the mean distance to neurovascular structures of 10.2 mm. The mean overpenetration was +5.2 threads (13 mm).
When compared with radiography-assisted fixation, our results show the risk for neurovascular injury
doubles with pin placement without fluoroscopic assistance. At less than 2%, this may be an acceptable rate in battlefield/mass casualty situations. This study also demonstrates that increased experience with standard fixation correlates to safer pin placement feel-placed fixation. In austere conditions, experienced surgeons can safely place external fixators without radiographic guidance.